Recommendations for power converter

[coglesby]

I have to run my generator for hours to recharge my 3 lead acid batteries after a cold night of running the furnace with the residential fridge. Thinking maybe I need to upgrade from my 55 amp converter to a 100 amp one. Any recommendations?

 

[Hoopy Frood]

12V or 6V batteries?

 

[coglesby]

3 12V Group 27

 

[el Rojo]

If you ever wanted an inverter, now is the time to think about both. The Victron Multiplus II charges the batteries at 120 amps. They are expensive at $1100, but it's the top of the line inverter charger.

 

[Soundsailor]

You could consider moving to LiFePo4 batteries. More capacity and faster charging are two positives that apply to the situation you describe.

 

[Scott'n'Wendy]

The LA batteries can't be charged faster anyway..no matter how big a charger you put on them. It's their chemical restriction. If you ramp up the voltage to force them to accept more charge current, you will significantly shorten their life.
Your solution is in buying LiFePO4 batteries

 

[coglesby]

The LA batteries can't be charged faster anyway..no matter how big a charger you put on them. It's their chemical restriction. If you ramp up the voltage to force them to accept more charge current, you will significantly shorten their life.
Your solution is in buying LiFePO4 batteries

I can charge them much faster with my heavy duty jumper cables with my truck, so apparently, it's not the batteries limiting charging in my specific case.

 

[coglesby]

If you ever wanted an inverter, now is the time to think about both. The Victron Multiplus II charges the batteries at 120 amps. They are expensive at $1100, but it's the top of the line inverter charger.

My unit already has an inverter that supplies my residential fridge.

 

[traveldawg]

Rec Pro? I'd be sure that if I was upgrading I would want a charger that could be changed to charge wet cell, AGM and Lithium.

For sure 100 amps would get the job done faster.

Li is certainly an option. But then there is the cost of new battery(s) and a charger. It would be the ultimate solution tho to 3 heavy wet cells.

 

[coglesby]

Rec Pro? I'd be sure that if I was upgrading I would want a charger that could be changed to charge wet cell, AGM and Lithium.

For sure 100 amps would get the job done faster.

Li is certainly an option. But then there is the cost of new battery(s) and a charger. It would be the ultimate solution tho to 3 heavy wet cells.

Best idea I have seen yet. I see RecPro has a 100A unit for $180 that works with lead and lithium. I would mount it in the front bay to keep distance to batteries down. Do you know if 33.3A is to fast of a charge for Group 27 LA battery.

 

[traveldawg]

Best idea I have seen yet. I see RecPro has a 100A unit for $180 that works with lead and lithium. I would mount it in the front bay to keep distance to batteries down. Do you know if 33.3A is to fast of a charge for Group 27 LA battery.

I have no idea. I'll let the battery experts chime in on that one.

 

[Scott'n'Wendy]

I can charge them much faster with my heavy duty jumper cables with my truck, so apparently, it's not the batteries limiting charging in my specific case.

Then you have small wires or bad/poor connections somewhere in the charge cct. 30amps is about max for those three batteries charged from the same charger without damage. Your 55amp charger is fully capable of that.
Soooo....maybe the battery disconnect switch has loose connections? Check the connections on the charger. Check the connections on the batteries to ensure they are clean and tight.

 

[coglesby]

Then you have small wires or bad/poor connections somewhere in the charge cct. 30amps is about max for those three batteries charged from the same charger without damage. Your 55amp charger is fully capable of that.
Soooo....maybe the battery disconnect switch has loose connections? Check the connections on the charger. Check the connections on the batteries to ensure they are clean and tight.

Your spot on.

After a little investigation, Only used 6 AWG wire and it runs to the power distribution panel then back to the batteries in the front storage.

 

[coglesby]

Why does it go to the powers panel. Is it fused there?

I’m thinking I need to cut the wire going from the battery disconnect to the power panel near the converter and wire the inverter in there. It’ll probably cut the distance from the battery disconnect to the converter down from 30 feet to 10 feet or maybe better yet, just move the converter to the front bay and tie into the battery disconnect there.

 

[traveldawg]

Why does it go to the powers panel. Is it fused there?

I’m thinking I need to cut the wire going from the battery disconnect to the power panel near the converter and wire the inverter in there. It’ll probably cut the distance from the battery disconnect to the converter down from 30 feet to 10 feet or maybe better yet, just move the converter to the front bay and tie into the battery disconnect there.

Good idea. The shorter the run from the converter to the batteries the better.

 

[Scott'n'Wendy]

Why does it go to the powers panel. Is it fused there?

It powers up all the 12vdc ccts from there

 

[Scott'n'Wendy]

or maybe better yet, just move the converter to the front bay and tie into the battery disconnect there.

The best place for the converter is close to the batteries.

 

[coglesby]

With my batteries depleted, I get about 13V at the batteries when the converter is on shore power. Merely a guess but the converter is probably not recognizing the batteries are depleted due to the voltage drop so probably not going into bulk mode.

 

[JPS350]

It might be worth while to install even a cheap battery monitor shunt at the battery so you can monitor charging current and voltage there. There was a similar discussion on the 22mle Facebook page about the poor performance of the stock charger.

I remember being pretty surprised when I saw the gauge of the wire they used on the run from the battery on mine. I'd have to check again to be sure but I'm thinking it is 8 awg and the the charger is about 3/4 of the trailer away.

I've never seen more than 13.8 volts on my 2 golf cart batts during charging or at full charge and charging current Is no where near what the charger should put out. Absorption voltage settings for FLA batteries should be well over 14v.

My solution, rather than tackling the wiring or existing charger inverter setup will be to install a 30A Victron bluesmart charger in the pass through right near the batteries and plug it into the outlet there with the appropriate sized wirng for the 10' run. Charging when on our generator should pick up considerably. That's the only time I have issues with the existing setup as it doesn't matter when we have electric to plug into and overnight to charge.

 

[coglesby]

Absorption on mine is 13.6V. Bulk is 14.4V. Seeing 13V at the battery on my voltage monitor makes me pretty certain it’s not getting to bulk mode so apparently fully discharged in absorption mode I’ve got a 0.6V drop from converter to batteries over the total run of ~30’.

I’m going to T the converter connection into the cable going from the power panel to the batteries instead of the converter going to the power panel then back to the batteries. I’ll put in 3AWG wire from the converter to the T. There will then be only less than 10ft of 6AWG wire in the path from the converter to the batteries reducing the voltage drop to 0.2V in absorption mode so I’ll get at least 13.4V at the batteries. Hopefully the increased current will reach the absorption mode max and the converter will go into bulk mode. I’ll find weekend after next.